A Cancer Research Center was established in the Department of Radiation Therapy, Harvard Medical School on November 1, 1971. It's purposes were: 1) To support Departmental research projects as they relate to cancer; 2) to provide research experience for residents in radiation therapy, post-doctoral fellows and medical students; 3) to promote interdisciplinary and interdepartmental research collaboration with experimental radiation therapy as a focal point; 4) to provide support for a seminar series in cell biology; and 5) to provide a mechanism for expansion of research activities. current research projects supported by the Center involve murine bone marrow stem cell kinetics, cellular and molecular effects of radiation, x-ray/drug interactions, tumor immunology, development of in vitro tumor models, radiation physics and studies on the functional structure of eukaryotei cell DNA. A salient feature of this Center is that pertinent laboratory information can be applied without delay to clinical problems and investigations initiated into the improvement of the overall management of patients with neoplastic disease especially with regard to radiotherapeutic strategy.